This section is intended to introduce the reader to various aspects of the art, which may be associated with exemplary embodiments of the present invention, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with information to facilitate a better understanding of particular techniques of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not necessarily as admissions of prior art.
Pipeline networks or fluid transportation assemblies are utilized as an efficient method for transporting fluid commodities from one location to another. These fluid commodities may include liquid commodities, such as hydrocarbons, heavy crude oils, lighter crude oils and/or refined products, such as diesel, gasoline, aviation fuel and kerosene. In addition, the fluid commodities may include gaseous commodities or two-phase commodities, such as ethane, for example. The pipeline networks may include various tubular members or pipeline segments coupled together with equipment in pump stations. The pump stations typically include one or more pumps, sensors (e.g. meters, transmitters or gauges) and/or flow control devices, for example. The pipeline networks provide an efficient mechanism for transporting the fluid commodities from one location to another. For instance, the pipeline network may provide a flow path from an oilfield production tree to a surface facility and/or storage facility. In another example, a pipeline network may transport fluid commodities from a refinery and/or storage facility to distribution locations for customers.
Because of the distances between the commodity staging locations, such as oilfield production trees and distribution locations, the pipeline networks typically span long distances (e.g. Interstate and Intrastate). To manage the pipeline networks efficiently, pipeline networks are typically operated from a central control center manned on a 24-hour basis by operators who monitor various operational settings associated with the transport of fluid commodities through the pipeline network. The operational settings may include equipment settings (e.g. equipment status, etc.) and measured parameters (e.g. pressure, temperature, flow rate, etc.). These operational settings are transmitted from the remote field locations (e.g. pump stations) back to the control center. The operational settings are typically stored and displayed by a computer-based system, such as a supervisory control and data acquisition (SCADA) unit). The operator may issue operational instructions that are converted by the SCADA unit into equipment settings and transmitted to the equipment at the remote field locations. Through the SCADA unit, the operators in the control center are able to monitor and manage the flow of fluid commodities through the pipeline networks.
However, the equipment in the pipeline networks may be set to a variety of different configurations that result in pipeline flow rate regimes for a given set of operational settings or conditions. That is, many different configurations of equipment settings may provide a desired flow rate. Yet, only one of the configurations is more efficient or optimized in comparison to the others. The operation of the pipeline networks is further compounded because operators typically monitor and manage multiple pipeline networks. With operator-to-operator response variations based on experience, training and other operator specific factors, the pipeline networks are generally operated at less than optimal, or, in a non-optimized configuration. As a result, the pipeline networks may experience reduced flow rates, excessive power losses across pipelines' valves, less than optimal variable frequency drive (VFD) settings and over/under-injection of drag-reducing agents (DRAs).
Other techniques have a limited ability to establish and sustain optimum conditions in the pipeline networks. Typically, other techniques, such as hydraulic modeling, model fluid commodities through simulators prior to the transport of the fluid commodities through the pipeline network. These simulations utilize conservation of mass, energy and flow equations to represent the fluid commodities. However, these techniques do not use real-time operational settings, empirical data and/or historical data from previous operational settings to operate the pipeline networks. Further, these other techniques do not provide recommendations concurrently with the transport of fluid commodities through the pipeline network (e.g. an online real-time expert PL control system that is integral to console operations and the SCADA system).
Accordingly, for any desired pipeline flow rate and a given set of operational settings, a mechanism, such as an empirically based expert pipeline control system, for providing the operator with an efficient or optimal configuration is needed. This mechanism may also automatically update certain settings, such as DRA, VFD, draw valves, etc., to maintain efficient operation of the pipeline.
Other related material may be found in at least U.S. Pat. No. 5,504,693; U.S. Pat. No. 6,799,195; U.S. Pat. No. 6,851,444; U.S. Pat. No. 6,961,753; and U.S. Patent Pub. No. 2005/0166961 now U.S. Pat. No. 7,389,787. In addition, further additional related material may be found in Sybille Handley-Schachler et al., “New Mathematical Techniques for the Optimisation of Oil and Gas Production System,” SPE European Petroleum Conference Oct. 24-25, 2000, Paper No. 65161-MA; Nestor Martinez-Romero et al., “Natural Gas Network Optimization and Sensibility Analysis,” SPE International Petroleum Conference and Exhibition in Mexico, Feb. 10-12 2002, Paper No. 74384-MS; M. K. Lane et al., Special Session: Energy Bridge LNG Projects: Technology Innovation to Date and Into the Future,” OTC 018397, 2006; and Mike Chunn et al. “Case History: New Gas Flow Computer Design Facilities Offshore Measurement in Gulf Coast Project,” OTC 008798, 1998.